Slide-cut shears.



F. S. POLLEY.

SLIDE GUT SHEARS.

ArPLIoATIoN FILED nso. ze, 1905. nmmwn nov.1o.,1sos.

915,697'.v Patented Mar.16,`1909.

rUNITIQD STATES. OFFICE.

t FRANK S. POLLEY, OF CHICAGO, ILLINOIS, ASSIGNOB, BY MESNE ASSIGNMENTS, TO SLIDING BLADE SHEAR COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SLIDE-CUT SHEARS.

Application filed December 26, 1905, Serial No. 293,197.

Specification of Letters Patent.

To all whom t'tmay concern:

Be it known that I, Finali S. Potter, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Slide-.Cut Shears, ef which the following is a specilication.

My invention relates to what are known as slide-.cut Shears and the object o f the invention is to produce shears of this character capable of cutting all kinds of goods with ease, evenness and certainty, and at the same .time retaining the keenness of their edges for a long period. To this end, in carrying eut my invention, I shape the adjacent surfaces of the blades so that they stand at an angle with reference to the plane in Which their cutting edges move, and .construct the blades and their connection so that they give a Slide or draw cut relative to each other as they are brought together, and also make the pivotal connections loose so that they will not hold the cutting edges in contact so as to cut and dull each other. In addition I prefer to form the cutting` edges of the shear blades in a slightly convex curve from their heels to the points.

In the accompanying drawings, which show the preferred embodiment of the invene tion, Figure l is a side elevation of a pair of shears containing my innirovements, with the blades open. Fig. 2 is a backfedge view, on an enlarged scale, of the bottom blade. Fig. 3 is a similar view ofthe top blade. Fig. 4 is an edge elevation of the shears with their blades closed so as to show the day-light between the blades, Fig. 5 is an end view, on an enlarged scale looking toward the points of the blades which are shown as closed together, Fig. 6 is a similar view of the top blade, Fig. 7 is a similar view of the bottom blade, Fig. S is a transverse section through the blades adjacent the heel ends thereof, and Fig. 9 is a similar section adjacent the point end.

In carrying vout my invention I form the shears with handles or thumb and linger holds ct and l), Shanks c and d, plate-,like eX- tensions c and f, and blades and k. The blades are loosely connected by a pivot screw n. The extensions e and]r have rides `or bearing surfaces .g and b, but the latter are not relied upon to keep the cutting edges of the blades in contact throughout the cutting Stroke, the pivotal connection between the blades not being tight enough to secure this result from the action of the rides. As a preferred means of producing endwise sliding of the blades in relation to eachother to secure the slide or draw cut, I offset the blades j and r with respect to the pivot screw n so that they extend forward from a location on the lower par-t of the extensions c andf as shown. The location `of the pivot screw n and the relation of the blades as shown are such that the cutting edge of one .of the blades and the back edge of the other are substantially in a line extending through the pivot, but it will be understood that this precise relation is not essential. Such shaping of the blades and the eccentric or ofi-set location ofthe pivot results in the cutting edges of the blades being given a draw out, which is characterized by well known advantages as compared with the cut of the .ordinary swinging blade.

The inner or adjacent surfaces l and .m of the top and bottom blades, respectively, are beveled or inclined transversely at an angle to the plane in which their cutting edges move, as will be clearly seen on reference to the drawings. This beveling of the inner faces of the blades may be produced in different ways and may be varied Within certain limits, but in practice I find it convenient to form the blades so that the angle, between their inner faces and the plane in which the cutting Vedges move, yincreases somewhat from the heels of the blades to their points. Thus, near the heels of the blades, as shown in Fig. 8,the angle between the surface Z or m and the plane in which the cutting edges move is very slight, the surface Z and'm at this peint being in fact practically parallel and in contact.` v,Nearer the points of the blades, as seen in Fi 9, the angle is increased considerably, an while the surfaces l and m at this point are at a .considerable angle to the plane in which the cutting edges move, they are still substantially parallel, and if the blades are brought together, they must necessarily be' separated by considerable space as only the edges are y in the plane referred to. This peculiar shape of the adjacent sur-face of the blades may be produced either by twisting the blades bodily or by grinding bevels on the adjacent faces of the blades, .or by both twisting the blades and grinding them. The space or opening which is thus made between the blades is known as day-light when the blades are closed as shown in Fig. 4. By giving the adjacent surface of the blades this beveled conformation, the cutting edges are left free to move in proper working contact or proximity throughout their length without the necessity of positively forcing them together, and by combining this construction with the slide or draw cut, the shearing action is effected with such ease that it is entirely practical to provide a pivotal connection thatis quite loose in all the working positions of the blades. The pivot n being formed and adjusted so as not to hold the cutting edges of thel blades in cutting contact, as has heretofore been considered essential, there is less friction between the cutting edges of the blades and they do not cut or chafe each other as in the case of the ordinary construee tion, so that as a result the shears can be worked much more easily than in the case of the ordinary construction, and they will also retain the lreenness of their edges for a much longer period.

lhile I preferably apply the twisting of the blade surface and the curving of the cutting edges to both blades, it will be apparent that I might apply these features to but only one of the blades, or that I might twist the adjacent surface of but one blade and curve the cutting edge of the other.

As previously stated, I prefer to form the blades with the angle betweenA the adjacent surfaces and the plane in which the cutting edges move increasing from the heels to the points of the blades, but it will be understood that this preference arises primarily from convenience of manufacture and is not necessary. It is clear, for exam le, that if the angle of the blades were made uniform rather than increasing from their heels to the points, the blades would still come into contact with each other only at their cutting edges. The essential thing is that the inner faces of the blades shall not come into positive engagement with each other in such a way that the cutting edges would not be free to come into contact or working `proximity with each other when the blades are opened and closed. This result can be obtained 1f the angle of the blades is uniform, as stated, and the angle may be very slight indeed, if the shears are well constructed. In this connection I would call attention to the fact that for clearness of illustration the degree of the angularity of the blades and the increase of the angularity from heel to point is considerably exaggerated in the drawings.

I have shown my invention as a plied to shears, but it is obvious that it is a so applicable to scissors.

What I claim is 1. In a pair of slide cut shears, the combination with the pair of blades of which one has its inner surface formed upon a curve having its transverse angle to the plane in which the cutting edges move increasing from its heel to its point, of means forming a loose pivotal connection between said blades.

2. In a pair of slide cut shears, the combination with the pair of blades of which one has its inner surface formed upon a curve having its transverse angle to the plane in which the cutting edges move increasing from its heel to its oint and its cutting edge formed in a slight y convex curve 'from its heel to its point, of means forming a loose pivotal connection between said blades.

3. In a pair of slide cut shears, the combination with the pair of blades having their inner adjacent surfaces formed upon curves having their transverse angles to the plane in which the cutting edges move increasing from their heels to their points, of means forming a loose pivotal connection between said blades.

4. In a pair of slide .cut shears, the combination with the pair of blades having their inner adjacent surfaces formed upon curves having their transverse angles to the plane in which the cutting edges move increasing from their heels to their points and their cutting edges formed on a slightly convex curve from their heels to their points, of means forming a loose pivotal connection between said blades.

5. In a pair of shears, the combination with the blades of which one has its inner surface formed upon a curve having its transverse angle to the plane in which the cutting edges move increasing from its heel to its point, of means loosely connecting said blades comprising a pivot pin offset from the longitudinal center lines of the blades.

6. In a pair of shears, the combination with the blades of which one has its inner surface formed on a curve having its transverse angle to the plane in which the cutting edges move increasing from its heel to its point and its cutting edges formed upon a slightly convex curve from its heel to its point, of means loosely connecting said blades comprising a pivot pin offset from the longitudinal center lines of the blades.

7. In a pair of shears, the combination with the blades having their inner adjacent surfaces formed upon curves having their transverse angles to the plane in which the cutting edges move increasing from their heels to their Voints, of means loosely connecting said b ades comprising a pivot pin offset from the longitudinal center lines of the blades.

8. In a pair of shears, the combination with the blades having their inner adjacent surfaces formed upon curves having their transverse angles to the plane in which the cutting edges move increasing from their heels to their points and having their cutting edges formed on slightly convex curves from their heels to their points, of means loosely connecting said blades comprising a pivot pin Offset from the longitudinal center lines of the blades.

9. In a air of shears, the combination with the b ades of which one has its inner surface beveled or inclined transversely at an angle to the lane in which the cutting edges of the bla es move, of means loosely connecting said blades comprising a pivot pin offset from the longitudinal center lines of the blades.

10. In a pair ofshears, the combination with the blades of which one has its inner surface beveled or inclined transversely at an angle to the plane in Which the cutting edges ofthe blades move and its cutting edge formed on a slightly convex curve, of means loosely connecting said blades comprising a pivot pin offset from the longitudinal center lines of the blades.

11. In a pair of shears, `the combination with the blades having their inner adjacent surfaces beveled or inclined transversely at an angle to the plane in which the cutting edges of the blades move, of means loosely connecting the blades comprising a pivot pin offset from the longitudinal center lines f of the blades.

12. In a pair of shears,` the combination of the blades having their inner adjacent surfaces beveled Or inclined transversely at an angle to the plane in Which the cutting edges move and their cutting edges formed upon slightly convex curves, of means loosely connecting the blades comprising the pivot pin offset from the longitudinal center lines Vof the blades.

13. In a pair of shears, the combination with the blades having their inner adjacent faces lying each Wholly on one side of the plane in Which the cutting edges move, of

means loosely connecting the blades com- L 

